A new green luminescent material Mg (L)2•H2O•CH3O (L = quinaldine acid) has been synthesized by the reaction of MgCl2•6H2O with quinaldine acid. The material was determined by X-ray single-crystal diffraction methods. The single-crystal X-ray analysis of Mg (II) complex reveals that the crystal belongs triclinic, space group P-1 with a = 0.71287(2) nm, b = 0.90375(3) nm, c = 1.08457(3) nm, α = 75.677(4), ß = 74.138(4), γ = 70.160(4). The luminescent properties of Mg (II) material were studied in solid and in organic solvents, respectively. The results show that the Mg (II) material emits green fluorescence.